Remus has spent the last three years wishing Sirius would kiss him.
Especially when Remus is hunched over his school work or a letter home, and Sirius leans over him, into him, to see what he's writing. So close and so warm and all lean muscle and heat. His warm breath tickles Remus' ear and it makes his insides twist and squirm themselves into joyous knots because it almost feels like Sirius is doing it on purpose even if-logically-Remus knows it is merely Sirius' disregard for personal space. He watches Sirius from the corner of his eyes and sees his lips lightly mouthing the words as he skims them over and, oh, all Remus wants to do is grab that face and snog him senseless.
Some days, he thinks maybe he could. Maybe Sirius would let him. Maybe Sirius would even kiss him back. Maybe, maybe, maybe.
But he's never bold enough to make the first move, because Sirius' mouth is so fond of kissing any pretty girl it comes across and Remus is neither of the girl variety nor particularly pretty. When Sirius is close and Remus has to hold his breath to keep from saying I love you and please please oh please kiss me already, he can almost forget all that.
Until he sees Sirius in the halls with those pretty girls, close then closer then kissing, and Remus is too aware of the ugly scars on his face or the too-big robes he's wearing that are frayed at the bottom and patched at the seams, or the way Sirius always squints at him and says You look so tired all the time, Moony...
Remus reminds himself that he doesn't stand a chance.